(L-R) Cast members Charlie Hunnam, Katey Sagal, and Kim Coates of drama the series "Sons of Anarchy" participate in a panel discussion during FX Networks' portion of the 2014 Television Critics Association Cable Summer Press Tour in Beverly Hills, California July 21, 2014.
REUTERS/Kevork Djansezian

Soon to trade his biker vest to an Excalibur, "Sons of Anarchy" lead star Charlie Hunnam is gushing over his co-star Maggie Siff, who played his wife Tara Knowles till the sixth season. The swansong season of FX's biker drama series is set to open 10 days after Tara's death, who was killed by SAMCRO's matriarch Gemma Teller (Katey Sagal).

Gearing up for a darker season after losing two of the show's main characters, Clay Morrow and Tara Knowles, SOA season 7 is expected to be full of vengeance and mayhem. Hunnam, who plays Jax Teller in the show, has relived his memories, with his charcater's wife, in the show's extra feature on the season 6 Blu-ray of "Sons of Anarchy."

Now available, the Blu-ray collection features the "Crimson Peak" actor talking about his relationship with Maggie Siff. "I really enjoyed working with her," revealed the Hollywood hunk. "And I think out of all the things we've achieved on Sons of Anarchy, the relationship between Jax and Tara is the thing that I find plays the most real and deep and rich and has been the thing I've been most proud of."

Calling it his "greatest collaboration with another actor," Hunnam is proud about his character and Tara's relationship in the show. Their story ended in season 6 finale, "A Mother's Work," with the death of Siff's character. Gemma stabbed the back of Tara's head multiple times, with a barbecue fork.

Series creator Kurt Sutter has talked about having difficulty writing the demise of two characters, who have been part of the show since the beginning, especially Tara's. Her specter is likely to linger for some time in season 7. In his previous interview, Sutter confirmed that there will be no flashbacks in the show's final season. Also, he is not keen on bringing dead characters back to life.

FX recently released a new trailer that features Jax tranforming into a Grim Reaper, as he hunts for Tara's cold blooded murder. With Nero establishing an alliance with The Mayans, the short clip features Jimmy Smits punching SAMCRO's president and telling Gemma. "Lots of people getting' killed, mama."

Fear and blood is the theme for the upcoming season, as the whole gang promises to support their president in his quest to take revenge. "Sons of Anarchy" Season 7 is scheduled to premiere on Sept. 9 on FX.